1. Field of the Invention
The present invention relates to an image capturing apparatus, an image capturing method and a storage medium storing a program for image capturing, suitable for use in, for example, digital cameras having a scene programming function.
2. Description of the Related Art
Many digital cameras have a scene programming function of first specifying a composition desirable for the object, a light-source environment, an image capturing pattern and the like, and then automatically setting any desirable image capturing mode.
One of the image capturing modes where the scene programming function can set is known as “night-scene/person” mode. In this image capturing mode, the object field depth is first set to a high value, and an image of a person is captured with a night scene as background, while illuminated with auxiliary light in an appropriate amount.
So-called “multi-exposure” image capturing is proposed (see, for example, Jpn. Pat. Appln. KOKAI Publication No, 2010-114566). In the multi-exposure image capturing, an image of an object in the foreground is first captured in the “night-scene/person” mode, while illuminated with auxiliary light. Next, an image of the object is continuously captured several times, while illuminated with no auxiliary light. Further, these images are corrected on the basis of the displacement between their characteristic points, and then combined to form a composite image. Finally, the composite image is further combined with the image of the object captured in the foreground to form a composite image.
The composite image thus formed is “a little dark” as a whole, because the shutter has been released several times and, therefore, for a long time. By contrast, an image obtained before the continuous image capturing is “very bright” in the foreground only and “very dark” in the background.
Consequently, the composite image obtained by the continuous image capturing greatly differs from the image obtained before the continuous image capturing, in luminance of not only the background but also the person in the foreground. Hence, it is difficult to perform a position adjustment between these images.